As described in publication 1, MEMS (Micro Electro Mechanical Systems) are devices into which a variety of mechanical, electronic, optical, chemical, and other functions are integrated by semiconductor micro fabrication technology (semiconductor processing) or the like.
Currently, the MEMS are used to develop microswitches (switches in micro size) using an electrostatic actuator.
One example of such a microswitch is disclosed in publication 2. FIGS. 28 and 29 are explanatory diagrams illustrating the switch of publication 2.
As shown in FIGS. 28 and 29, the microswitch has a seesaw-type structure. The microswitch has a column (supporting leg) 84 and a beam 81. The column 84 is provided at a center of the microswitch. The beam 81 has a narrow-plate shape, and is provided with electrodes respectively at both ends.
On such parts of the substrate as to respectively oppose both ends of the beam 81, absorbing electrodes (electrostatic force applying electrodes) 82 and substrate contact points 83 are provided. When an electric field is applied to one of the absorbing electrodes 82, the beam 81 is absorbed to the substrate. In this way, switching operation for connecting one of the electrodes of the beam 81 and one of the substrate contact points 83 is performed.
Thus, the seesaw-type structure of the microswitch allows for driving the beam 81 at a low voltage.
However, according to the microswitch of publication 2, the beam 81 (which has a narrow-plate shape) can only perform up-and-down movement, using the column 84 as an axis of rotation. Therefore, the microswitch of publication 2 has a drawback that the substrate contact points 83 can be provided only in two directions along which the beam 81 extends.
Publication 1: “Current Situation of MEMS Technology and Its Problems”, Technology Evaluation and Research Report (Technology Trend), No. 3 (published on Mar. 28, 2003 by Ministry of Economy, Trade, and Industry, Industrial Science And Technology Policy and Environment Bureau, Technology Evaluation and Research Division, Manufacturing Industries Bureau, Industrial Machinery Division)
Publication 2: Japanese Publication for Unexamined Patent Application, Tokukai 2002-287045 (publication date: Oct. 3, 2002)